Caption: Dog faeces contain large quantities of bacteria and other microorganisms. High numbers of dogs in the urban environment and their habit to defecate on sidewalks, on playgrounds and in other places frequented by the general public means that such places are being contaminated with faecal materials. Rain and wind make this material airborne. Breathing may bring the microorganisms to human lungs and cause diseases. It is important to obey municipal bylaws and to collect dog faeces and dispose of them properly in the toilets. Enhanced SEM. Image width: 19.7 micrometers. Magnification: 5,075x if the image is printed 10 cm wide.